【作者】 李璇；

【导师】 施荣华；

【作者基本信息】 中南大学 ， 通信与信息系统， 2005， 硕士

【摘要】 人脸由于其自身的稳定性和个体差异性,成为生物特征身份验证的理想依据,因此人脸识别技术是当今安全技术中研究的热门课题。此外,人脸识别还具有直接、友好、方便等特点,将人脸识别技术应用于存取控制系统,与身份识别卡、密码等传统手段配合使用可以更好的提高系统的安全性能和使用性。 本文将人脸识别技术与存取控制技术有机的结合起来,提出了一种可靠的基于人脸识别技术的存取控制方案。系统以人脸识别技术作为用户的身份认证模块,以基于特征码和双向认证的RBAC作为权限分配模块。 人脸检测部分基于人脸肤色信息和几何特征信息提出了一种快速、稳定的人脸检测算法。算法采用由粗到细的检测策略,先通过肤色信息对图像进行预检测以获取人脸候选区域,然后结合人脸几何特征进行二次确认。算法对复杂背景、尺寸、旋转角度等细节具有很好的适应性。人脸识别部分采用PCA与BP神经网络相结合的识别算法,并引入参考特征脸集合概念提出了一种快速的人脸识别策略。人脸识别时,通过求得待识别人脸与参考特征脸集合中各个脸的距离向量来缩小搜索空间,对于人脸数量较多的情况具有很好的应用价值。存取控制部分采用基于角色的存取控制模型(RBAC),并结合素数特征码的唯一分解特性、角色环境参数函数和基于Harn双向数字签名方案很好的解决了传统RBAC在具体实现过程中角色私有权限和公有权限分开继承、角色权限动态约束问题以及访问许可权限在传输过程中的安全加密问题。方案实现简单、安全、动态适应性强。更多还原

【Abstract】 Face recognition is a hot subject in the study fields of security technology. This article, integrating face recognition technology into access control system, brings forward a new scheme which can promote the security of system.The new system adopts the face recognization technology as its authentication part and RBAC based on identity code and double-way authentication as its permission assignment part.In face detection part, this article brings forward a quick, efficient and steady face detection algorithm based on skin color and geometry characteristics information. First, this algorithm adopts a coarse to fine strategy, the face candidates is detected first by skin color information, then the face candidates are cross-checked by geometry characteristics. This algorithm is proved to be efficient and robust to the images in different background, size and rotation angles.In face recognition part, this article adopts the arithmetic of PCA and BPNN and introduces the concept of reference Eigenface aggregate to enhance the speed of face recognition. The distance vector of face candidate to the reference Eigenface aggregate is calculated firstly, and then a small aggregate of faces can be selected by the vector. At last, the face candidate validates the small aggregate one by one with BPNN trained before. This scheme is very efficient when the number of face is great.In access control part, this article adopts role-based access control (RBAC) and brings forward a new scheme for access control with identity code, role environment function and double-way authentication based on Harn digital signature, which solves the problems of public permission and private permission inherited independently in role hierarchies, dynamic constraints for role’s permission and system security. The new scheme is secure and easy to implement.更多还原